We propose the establishment of a Southern California Center for Children's Environmental Health and Disease Prevention Research with the goal of understanding how host susceptibility and environmental exposures determine children's respiratory disease. The goals are: (1) to study childhood determinants of respiratory susceptibility to air pollution; (2) to assess the modulation of allergic inflammation by environmental tobacco smoke (ETS); and (3) to determine whether intervention measures can: reduce sensitization to cockroach and dust mite, and improve the health of in asthmatic children. To accomplish these goals we have assembled an interdisciplinary team of investigators from two major Southern California at Los Angeles. Community-based organizations will actively participate in the planning and conduct of the studies. The research projects will rely on interdisciplinary approaches: exposure assessment including in-home sampling and biomarkers; novel study designs, including state-of-the-art statistical and epidemiologic approaches; and the basic and applied sciences, including physiology, immunology, molecular biology, genetics, and clinical medicine. This proposed Center will interface with the existing NIEHS-funded Souther California Environmental Health Sciences Center (SCEHSC). This interaction will result in efficiencies and synergism as existing Facility Cores such as exposure assessment, biostatistics and molecular biology will provide support for the proposed Center activities. The Center's Administrative Core will oversee the operation and interactions of the basic research projects, the community-based intervention/prevention program, Facility Cores, community organizations, and the New Scientist Program, which will attract new investigators to the Center. The Internal and External Advisory Committees will guide current and future directions of the Center and its research activities. The proposed Center has many strengths on which to develop a strong multi- disciplinary environmental research program for children: a critical mass of interdisciplinary investigators and resources, a track record of academic excellence and productivity, and established and deep commitment to respiratory environmental health problems connections to the SCEHSC, and a large multi-ethnic population of children in Southern California. The proposed Center will enhance interdisciplinary research in children's respiratory health by providing the setting and mechanisms for learning about fundamental and practical aspects of important environmental agents and exposures.